Hathway — Company giving low grade router

I have taken 100 mbps plan. The company has provided low grade router in which i am getting 20-40 mbps speed. When i have raised complaint the executive asked to change router if i change my existing plan to 150 mbps plan. But the problem is some executives are saying that i have to take plan for 3 months and some are saying i have take minimum of 6 month plan. I have also agreed to this but the problem is currently i have taken 100 mbps plan for 3 months and 1 month is still remaining. So according to them if i take the plan now i will be losing my one month benifit. This is really fraud. The company is really looting it's customer.